A. Field of the Invention
The present invention relates to a PDP (Plasma Display Panel) and, more particularly, to a PDP substrate structure and its fabricating method.
B. Description of the Prior Art
A general color PDP, as shown in FIG. 1, has upper and lower structures. The upper structure comprises an upper substrate 1, a sustain electrode 3 formed on the upper substrate, a dielectric layer 4 for maintaining the surface charge generated during a discharge of the sustain electrode 3, and a protection layer 5. The lower structure comprises a lower substrate 2, and an address electrode 6 formed on the lower substrate 2. Barriers 7 coated with phosphor 8 are formed between the upper and lower substrates 1 and 2. A frit glass 9 is formed at the glass end portion, combining the upper and lower substrates 1 and 2.
Reference numeral 10 indicates a discharging gas sealed in a space between the upper and lower structures.
It is considered that the PDPs are the most suitable flat display device because they can display images at high speed and allow the manufacture of large-sized panels. In the past, AC and DC type PDPs having two electrodes have been used, and out of the two types of PDP, a surface discharge type AC PDP is considered to be the more suitable device for a color display.
To manufacture a conventional PDP, a pattern is first formed on the upper substrate 1 that has transparent electrodes. The side end portions of the transparent electrodes are coated with a metal that exhibits lower resistance than the transparent electrodes, so that the line resistance between the end portions of the electrodes can be reduced and thereby the quality deterioration of the sustain electrode 3 due to a driving voltage drop can be prevented. In another method of manufacturing the PDP, opaque metal electrodes are used instead of the transparent electrodes, and the dielectric layer 4 is formed on the whole surface of the electrodes to restrict the discharging current. The protection layer 5 is deposited on the whole surface, generally by an E-beam deposition using magnesium oxide, in order to protect the dielectric layer 4 against a sputtering that occurs during a discharge of the dielectric layer 4.
An electrode is formed vertically with respect to the two electrodes on the lower substrate 2, and barriers 7 are deposited between the electrodes so as to prevent a mis-discharge in the adjacent discharge regions. Between the upper and lower substrates 1 and 2, combined with the frit glass 9, is filled with the discharging gas 10 and sealed completely.
When a voltage is applied to the sustain electrode 3 and the address electrode 6 of the finished PDP, a discharge takes place in the discharge region 10 on the surface of the dielectric and protection layers 4 and 5, generating ultraviolet rays.
While the electrons that exist in a discharge cell are accelerated toward the negative (-) electrode by the driving voltage applied, and collide with the mixture of inert gases filled in the discharge cell, the inert gases are excited to emit the ultraviolet rays.
The ultraviolet rays then collide with the phosphor 8 formed as thick as a predetermined thickness around the address electrode 6 and the barriers 7, generating visible rays to display a color image.
However, the conventional plasma display panel presents some disadvantages in that the panel whose life is at most about 5,000 hours needs a structural improvement to secure long life more than 30,000 hours. Moreover, the protection layer is generally formed by E-beam deposition and such formation by E-beam deposition results in low productivity because of the need for complicated process such as vacuum and heat treatments and the expensive equipment required therefor, thus raising the unit cost of products.